1. Field of the Invention
The present invention relates to a parameter setting apparatus provided with a display unit having a touch screen. The present invention also relates to a computer program and a parameter setting method applied to the parameter setting apparatus.
2. Description of the Related Art
Conventionally, many digital audio mixers and electronic musical instruments have employed an apparatus for setting parameters using a touch screen (also referred to as a touch panel). A touch screen is an input/output apparatus for displaying images as well as sensing touch of a finger, stylus or the like on a display screen and the position of the touch operation. On the touch screen, operators are displayed to allow a user to touch the display area of an operator with his finger, resulting in the value of a parameter assigned to the operator being input in accordance with the movement of the finger. In a case where the operators are on/off buttons, each touch on the on/off button with a finger or the like reverses the on/off state of the on/off parameter assigned to the on/off button.
Parameter setting through the use of the touch screen is easy for a user to operate. When compared with cases where a mouse having switches is used, however, the touch screen allows the user to recognize his touch operations only through the sounds of touches and changes of display screen. As a result, it is quite burdensome for the user to touch every single on/off button to reverse the on/off state of on/off parameters assigned to the on/off buttons without fault. In many cases, in addition, on the display screen, various types of on/off buttons are displayed altogether. In other words, on/off buttons adjacent to an on/off button which the user has touched to operate are not necessarily those the user desires to operate. In those cases, it is difficult for the user to negotiate around unnecessary buttons and touch only his desired on/off buttons.